成煤作用早期阶段植物-腐植体-镜质体分子结构演化机制

煤炭形成机制是煤地质学基础课题，其对煤炭及煤系伴生资源勘探开发、古环境重建均具有重要意义。项目以分子结构演化为主线，探究成煤作用早期阶段植物-腐植体-镜质体的演化机制。拟基于碳13核磁共振等实验表征植物、泥炭、褐煤腐植体、长焰煤镜质体分子结构特征，利用显微红外等实验原位表征煤样及植物化石中腐植体、镜质体化学基团特征，构建典型植物成分、腐植体、镜质体分子结构模型。结合微生物模拟实验、分子模拟方法（REMD力场）及生物地球化学理论，探究生物地球化学作用下分子结构降解、转化机理；基于有机地球化学理论及分子模拟方法（ReaxFF力场），探究热-时间作用下分子结构演变机理。综合实验与分子模拟结果，阐明植物-腐植体-镜质体分子结构演化规律，以解决“成煤作用早期阶段植物-腐植体-镜质体分子结构演化机制”这一科学问题，为低煤阶煤高效利用、低煤阶煤层气勘探开发及煤分子中关键地质信息解析提供科学支撑。

The forming process of coal is one of the key and basic topics in coal geology. It is of great significance to the utilization of coal resources, the exploration of coal-measuring mineral and gas resources, and the reconstruction of paleoenvironment. The project focuses on the evolution of molecular structure to explore the evolution mechanism of plant-huminite-vitrinite during peatification and early coalification process. It is proposed to characterize molecular structure of plants, peats, huminite in brown coals, and vitrinite in long flame coals based on 13C nuclear magnetic resonance and other experiments. Micro-FTIR experiments will be used to characterize the molecular structure of himinite and vitrinite in situ in coal samples and fossil samples. Then, the molecular structures of typical plant components, huminite and vitrinite will be reconstructed. The evolution mechanism of molecular structure under the action of biogeochemistry will be explored by combining the microbial decomposition simulation experiment, molecular simulation (REMD force field) and biogeochemical theory. And the evolution mechanism of molecular structure under the action of heat and time will be studied based on organic geochemistry theory and molecular simulation (ReaxFF force field). By comprehensive analysis of the experimental results and molecular simulation results, the molecular evolution of plant-huminite-vitrinite will be clarified, to solve the scientific problem: “the evolution mechanism of plant-huminite-vitrinite molecular structure during peatification and early coalification process”. The project will provide scientific support for the highly efficient utilization of low-rank coal, the exploration of low-rank coalbed methane, and the analysis of key geological information in coal molecule.